From Laboratory towards Industrial Operation: Biomarkers for Acidophilic Metabolic Activity in Bioleaching Systems
| Autor: | Cecilia Demergasso, Mauricio Acosta, Sabrina Marín, Camila Escuti, Karla Delgado, Diego Ayma, Mayra Cortés |
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| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
0301 basic medicine
lcsh:QH426-470 heap leaching Leptospirillum ferriphilum Acidithiobacillus 030106 microbiology Heap leaching acidophilic bacteria Article decision making Ferrous 03 medical and health sciences Industrial Microbiology Copper extraction techniques Bioleaching metabolic monitoring Genetics Leaching (agriculture) Genetics (clinical) Heap (data structure) relative gene expression biology Bacteria RT-qPCR Biodiversity Pulp and paper industry biology.organism_classification lcsh:Genetics 030104 developmental biology Microbial population biology genetic markers Environmental science Laboratories RT‐qPCR Acids Biomarkers Copper |
| Zdroj: | Genes, Vol 12, Iss 474, p 474 (2021) Genes Volume 12 Issue 4 |
| ISSN: | 2073-4425 |
| Popis: | In the actual mining scenario, copper bioleaching, mainly raw mined material known as run-of-mine (ROM) copper bioleaching, is the best alternative for the treatment of marginal resources that are not currently considered part of the profitable reserves because of the cost associated with leading technologies in copper extraction. It is foreseen that bioleaching will play a complementary role in either concentration—as it does in Minera Escondida Ltd. (MEL)—or chloride main leaching plants. In that way, it will be possible to maximize mines with installed solvent-extraction and electrowinning capacities that have not been operative since the depletion of their oxide ores. One of the main obstacles for widening bioleaching technology applications is the lack of knowledge about the key events and the attributes of the technology’s critical events at the industrial level and mainly in ROM copper bioleaching industrial operations. It is relevant to assess the bed environment where the bacteria–mineral interaction occurs to learn about the limiting factors determining the leaching rate. Thus, due to inability to accurately determine in-situ key variables, their indirect assessment was evaluated by quantifying microbial metabolic-associated responses. Several candidate marker genes were selected to represent the predominant components of the microbial community inhabiting the industrial heap and the metabolisms involved in microbial responses to changes in the heap environment that affect the process performance. The microbial community’s predominant components were Acidithiobacillus ferrooxidans, At. thiooxidans, Leptospirillum ferriphilum, and Sulfobacillus sp. Oxygen reduction, CO2 and N2 fixation/uptake, iron and sulfur oxidation, and response to osmotic stress were the metabolisms selected regarding research results previously reported in the system. After that, qPCR primers for each candidate gene were designed and validated. The expression profile of the selected genes vs. environmental key variables in pure cultures, column-leaching tests, and the industrial bioleaching heap was defined. We presented the results obtained from the industrial validation of the marker genes selected for assessing CO2 and N2 availability, osmotic stress response, as well as ferrous iron and sulfur oxidation activity in the bioleaching heap process of MEL. We demonstrated that molecular markers are useful for assessing limiting factors like nutrients and air supply, and the impact of the quality of recycled solutions. We also learned about the attributes of variables like CO2, ammonium, and sulfate levels that affect the industrial ROM-scale operation. |
| Databáze: | OpenAIRE |
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